The present invention relates generally to the field of telecommunications and, in particular, to a network amplifier for a cable network.
Cable networks are a common medium for providing video, audio and other data or programming to subscribers. Conventionally, cable networks have one or more head ends that transmit signals to subscribers over a medium that includes coaxial cable. Cable networks typically provide subscribers with programming on a variety of channels. Each channel occupies a distinct frequency band on the coaxial cable.
Signals transmitted over a coaxial cable tend to attenuate or decrease in signal strength or magnitude as the signals propagate away from the head end. Cable networks typically include network amplifiers that are placed at various locations in the cable network. The network amplifiers increase the magnitude of the signals to compensate for the attenuation due to the distance that the signals have propagated.
The network amplifiers typically are formed of a number of circuit components that are interconnected on a printed circuit board. Once the amplifier is installed, the housing is sealed and the amplifier cannot be modified without opening the housing. Unfortunately, this may be a difficult and sometimes labor intensive process. Further, many of the circuit components can only be changed (e.g., the amount of attenuation provided by an attenuation pad) by replacing the part.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for an improved network amplifier.
The above mentioned problems with network amplifiers and other problems are addressed by the present invention and will be understood by reading and studying the following specification. A network amplifier is described which uses a microprocessor to control a variable attenuator and a variable equalizer to provide automatic gain control for the network amplifier.